On 4/11/25 07:36, Kohei Tokunaga wrote:
Hi Pierrick, thank you for the feedback.
> first, congrats for this work!
> It would be really nice to have this available upstream, starting with a
> modest TCI port, before having the tcg backend also.
Sure, I'll split the patch series, starting with the TCI port.
> Do you have recent information about wasm64? It seems to be something
> that has been discussed for several years, without really seeing any
> progress.
According to the adoption status [1], wasm64 is supported by recent versions
of Chrome and Firefox. Emscripten also supports wasm64 [2]. However, it is
not yet supported by Safari or libffi [3], and I haven't found a roadmap for
the adoption.
Great, I didn't notice major browsers were already supporting it.
Even if Safari does not support it, maybe having the two other major
ones would be enough to target this.
Regarding libffi, our usage of it seems limited in tci, I wonder if we
could not workaround this. Or eventually see if enabling wasm64 is a big
work in libffi itself.
[1] https://webassembly.org/features/ <https://webassembly.org/features/>
[2] https://emscripten.org/docs/tools_reference/
settings_reference.html#memory64 <https://emscripten.org/docs/
tools_reference/settings_reference.html#memory64>
[3] https://github.com/libffi/libffi/
blob/6a99edb8082f75e523e0d6ebaba42218b80e10c8/README.md#supported-
platforms <https://github.com/libffi/libffi/
blob/6a99edb8082f75e523e0d6ebaba42218b80e10c8/README.md#supported-platforms>
> As Philippe said, we can't really revert that (it's now an assumption
> for our softmmu implementation, and would break code if we enabled it
> again now.)
>
> That said, we can always have a first version supporting only 32 bits
> targets. And later, when wasm64 will be available, we can extend this to
> all remaining ones.
The main challenge I'm seeing is that I couldn't find a clear timeline for
wasm64 adoption so it's difficult to predict when it will be widely
available.
Regarding the revert, the wasm backend supports 64-bit words, so the revert
introduced in patch 06/10 is partial, as also pointed out by Paolo.
Ok, thanks for pointing it, I didn't really read into details of the
patch, and simply assumed you wanted to revert this change completely.
If we can have a solution only affecting emscripten builds, I think it's ok.
Regards,
Pierrick
